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Mars and Jupiter

StarDate:

October 15, 2015

Two planets in the morning sky almost look like they’re going to ram together over the next few days. Worry not, though — they’re hundreds of millions of miles apart.

The brighter of these worlds is Jupiter, the largest planet in the solar system. It’s the second-brightest object in the sky at that hour. It’s outshined only by Venus, the “morning star,” which is not far to Jupiter’s upper right.

For the next few days, though, Jupiter has an even closer companion: Mars. It’ll stand just above Jupiter tomorrow, and move closer to the giant planet on Saturday and Sunday. Orange Mars is only a fraction as bright as Jupiter, but it’s still quite easy to pick out.

Both planets are moving up and away from the Sun as seen from Earth. But Jupiter is moving a little faster. In fact, though, that’s a bit of an optical illusion. Mars actually moves faster in its orbit around the Sun than Jupiter does. Because of our shifting perspective on the planets, though, Jupiter looks like the swifter one.

One other illusion is their togetherness. While it looks like they’re almost close enough to touch each other, the two planets are quite a ways apart — roughly 350 million miles. So despite appearances, there’s no chance that these two worlds will get in each other’s way as they creep past each other in the morning sky.

Look for Mars and Jupiter well up in the east at first light, with brilliant Venus looking down upon them.

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